Computer wouldn't boot

My computer operated as normal yesterday a.m. and shut down normally. Last evening, when attempting to start it, the power light came on, the drive light flashed for a short time then went off, the monitor showed a message "no signal" and the screen remained blank with the little yellow light at the bottom of the monitor. There was no post, no splash screen for asus, no sound, just the power light.
It is an asus motherboard, Pentium IV 2.4, 2 g ram, Radeon 7000 video card, XP pro, integrated sound and network cards.
When I turned it on this AM, it started to boot and got to the screen talking about an unusual shutdown, I went with safe mode, logged in as administrator and restarted. I came up normally and I attempted to backup my quicken. When I tried to burn a disk of the backup, it locked up. I had to shut it down and I got the no boot situation again. I just let it alone for 3/4 of an hour or so and retried. This time it booted, I burned the backup and have been using it for about 45 min.
It sounds like a heat problem to me but I really don't know what to check. Temp here yesterday was about 94 but this should not be a problem. The placement is the same as last summer and the only change is the new motherboard which I struggled with here a few months ago. I hope this one is not giving up the ghost already.
Does anyone have a suggestion how to proceed. Thank you for your help.

Re: Computer wouldn't boot

There could be an issue with your power supply dying out. If you have a spare i'd try swapping it out and seeing if that solves the problem. I don't know the wattage of your PS or how many components you have hooked up, but i've had similar problems to what you listed and the remedy in my situation was the PS. it sounds like the PS especially when you say that you at one point had no post. If not, it probably is something over heating... if the CPU isn't properly cooled the same thing can happen.

Re: Computer wouldn't boot

Thank you for the response John. My power supply is 350 w, running 2 hard drives, one dvd burner, diskette drive and one case fan. After it functioned ok the other am, I was again unable to start it that evening nor since. I think I'll try removing the cpu cleaning and renewing the heat transfer stuff on the heat sink and checking all my leads, plugins, memory, etc. I don't have another ps to try so if nothing happens with the above, I'll pick one up and replace the current one.
Ray

Re: Computer wouldn't boot

I tried removing the cpu and renewing the heat sink compound, pulled all the connectors and memory and put everything back together. Still no go.

The hard drives are running, the power led is on, the drive led comes on for a while, the power indicator led on the motherboard is on and both the processor and case fans are running. Do you still feel that the Power Supply could be the culprit? I haven't checked voltages on each of the PS leads.

When I turn the computer on, the monitor logo is shown briefly, then the error message showing "no signal" is displayed for about 10 sec. and then the screen just goes black. As the computer is turned on, you can here the fans run and the hard drives spinning up, there is no post beep nor is any boot or bios information shown on the screen.

In the past when I had problems, at least there were symptoms which hinted at the course of action, but here it looks like I will just have to start buying parts.

Re: Computer wouldn't boot

I gotta say, with what you just described it sounds as though the CPU is the problem. They can burn out - especially if the thermal paste that connects it to the heat sink isn't properly applied. my friend lost 3 in a row that way because they burn out in under a second of use with no thermal paste to efficiently transfer the heat generated from the CPU to the heat sink. Don't go out and buy a PS just yet since the HD's are running and signals show signs of stable power, i would no longer suggest replacing the PS at this point. I also don't think the problem is the motherboard since power is going to all the different components, which sounds like its doing its job OK still.

If the monitor screen is blank, it sounds like the video card (or onboard video) is alive and transmitting some signal which would also indicate the motherboard is OK, but with nothing displayed the CPU is not doing its job. It sounds from those symptoms that your best option is trying to replace the CPU.

Re: Computer wouldn't boot

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Thank you John, I really appreciate your attempting to help me through this. I know its been a while since I posted and I thought I'd try to bring you up to date. I purchased a new CPU and installed it. I was very careful to follow the recommendations for installing the heatsink with heat sink compound (http://www.pcguide.com/proc/physinst/sink.htm) I followed the procedures to the letter and used the Radio Shack 276-1372 compound.
When I plugged the unit in and turned it on it booted as it should. I was reading mail and went to minimize the Eudora program and all three buttons (minimize, full screen, close) disappeared. Everything else on the screen stayed the same but the computer froze. Then the internal speaker started squealing and I shut it down with the power strip switch. After about five minutes, I turned it on again and and it booted normally though it did not do a scandisk for shutting it down the way I did. Used it for an hour or so, found that networking with my wife's laptop was not working (she could not see this machine, I could never see hers), left it on a while and then shut it down and went to bed.
The next morning it booted normally and I again read mail, did some browsing and tried to use photoshop to edit a picture. When I attempted to crop a pic, it said my scratch drive wasn't big enough to complete the task. When I checked the drive C: size (30g total) it now showed 85-90% full. This drive was only 55% full when this problem started a couple weeks ago and I never had problems handling any Photoshop tasks before. I shut it down and had to go to work.
When I got home, I thought I'd try to find out what kind of files were clogging up the drive. Maybe temp files while unsuccessfully trying to boot the drive before?? I turned the computer on and got the "no signal" on my monitor and again no post beep, the drives are spinning up, the indicator lights for power and drive are on just like before with a blank black screen. I thought maybe there was a problem with the motherboard/bios since the normal bootup screen doesn't come up at all. So I ordered another mb like the one I have currently to see if that is the problem. That should arrive tomorrow.
Yesterday, I installed a known working power supply and this did not make any change in the way the computer acts. Do you or anyone else reading the forum have any opinions as to what is going on? Whenever I had problems before, I could use "safe mode", go into the bios, run diagnostic software, scan for stuff, etc. etc. This is really frustrating. It would be nice if I could keep dumping money into this project but I can't and I am running out of options. Thank you for your interest.
Ray

Re: Computer wouldn't boot

Hi Ray,

Which model of the ASUS motherboard are you using? A few months back I built a new system using the ASUS P5LD2 Deluxe motherboard and used what I thought was a reasonable Antec PSU 550w. I experienced similar problems to yours. It turned out that the Antec 550W PSU didn't have the right amount of amps for the ASUS motherboard. A change of PSUs with higher amp output corrected the problem. It took several days of my time and 10 hours of my supplier's tech support time to arrive at the solution... which was a really weird problem.

ASUS motherboards also come with PC Probe, a software utility that monitors fans, CPU and M/B and temperatures. Perhaps when you rebuild your system you may want to install PC Probe to help determine if you have a heat problem.

Re: Computer wouldn't boot

Hi Bob,

My board is an ASUS P4P800 SE which I installed from Feb to March of this year. See <post:=546,038>post 546,038</post:>. I was having intermittent problems with internet throughput and memory errors and so changed the motherboard from an SIS generic board to this Intel Chip ASUS. Once the board was finally installed and the software system rebuilt, the computer ran like a champ with a 350W PS till just before the start of this post. When I tried another Power Supply the other day, it was 430W and it didn't make any difference in the operation of the unit.

My new P4P800 SE board showed up today from newegg and I'll probably install it tomorrow. This board seems to have gotten good reviews but I'm not really that optimistic that this is going to take care of my problem. The thing I am most afraid of is that I have fried a second CPU (though I really don't know if my old one was damaged or not).

Thanks Bob for the information. I'll have to go with the stuff I have to work with now and if no progress is made, the PS route will be next.

Would you think that a dead video card could be the problem? That it is just not sending any data to the monitor? Does anyone have any experience with a dead video card and what the symptoms would be? This one is an ATI Radeon 7600 which I recently upgraded the drivers for because google earth would not work without streaky or blocky artifacts on the maps.

Re: Computer wouldn't boot

Hi Ray,

I checked the specs of the ASUS P4P800 SE at the ASUS site and it appears to be a decent m/b. The specs state that it supports AGP 8x/4x with 0.8v, 1.5v only. I searched for your stated video card, the ATI Radeon 7600, and cannot find anything regarding that model. Is it possible that you meant 9600? Since there is no onboard video with the P4P800 SE (at least not what I could see at the ASUS site) could you perhaps borrower a suitable video card and see if your video problems disappear?

Re: Computer wouldn't boot

Hi Bob,

Sorry for the bum steer, the card is a RADEON 7000 64M DDR and was purchased about three years ago. I have a lead on the borrow of an appropriate card this weekend and I'll let you know how I make out. Thanks for your suggestions.

I haven't opened the new m/b box yet and if the card turns out to be the culprit, I will probably try to return it.

Re: Computer wouldn't boot

Well I tried another video card, though it was a pci and not an agp card and the result was the same as with the current one. I was just hoping for the bios to come up but nope. "no signal" and then nothing. After reading more on the topic, I tried resetting the bios and unhooking everything except the c drive, mouse, keyboard, monitor and used one memory stick. Still no dice.
Since the only thing that brought the unit to life, (though only for a few hours) was replacing the cpu, I decided not to install the new motherboard. I am going to try to send it back and take the unit to a repair shop in the next town. They have a very good reputation for repair work. I don't have any test equipment nor spare parts to try out to track this down and I can't keep buying stuff to try.
Thanks very much for the assistance John and Bob. I wish we could have worked it out. Maybe next time. Thanks again.
Ray